Estimating excess visual loss in people with neovascular age-related macular degeneration during the COVID-19 pandemic

ObjectivesTo report the reduction in new neovascular age-related macular degeneration (nAMD) referrals during the COVID-19 pandemic and estimate the impact of delayed treatment on visual outcomes at one year. DesignRetrospective clinical audit and simulation model. SettingMultiple UK NHS ophthalmology centres. ParticipantsData on the reduction in new nAMD referrals was obtained from four NHS Trusts in England comparing April 2020 to April 2019. To estimate the potential impact on one-year visual outcomes, a stratified bootstrap simulation model was developed drawing on an electronic medical records dataset of 20,825 nAMD eyes from 27 NHS Trusts. Main outcome measuresSimulated mean visual acuity and proportions of eyes with vision [≤]6/60, [≤]6/24 and [≥]6/12 at one year under four hypothetical scenarios: no treatment delay, 3, 6 and 9-month treatment delays. Estimated additional number of eyes with vision [≤]6/60 at one year nationally. ResultsThe number of nAMD referrals at four major eye treatment hospital groups based in England dropped on average by 72% (range 65 to 87%) in April 2020 compared to April 2019. Simulated one-year visual outcomes for 1000 nAMD eyes with a 3-month treatment delay suggested an increase in the proportion of eyes with vision [≤]6/60 from 15.5% (13.2 to 17.9) to 23.3% (20.7 to25.9), and a decrease in the proportion of eyes with vision [≥]6/12 (driving vision) from 35.1% (32.1 to 38.1) to 26.4% (23.8 to29.2). Outcomes worsened incrementally with longer modelled delays. Assuming nAMD referrals are reduced to this level at the national level for only one month, these simulated results suggest an additional 186-365 eyes with vision [≤]6/60 at one-year with even a short treatment delay. ConclusionsWe report a large decrease in nAMD referrals during the first month of COVID-19 lockdown and provide an important public health message regarding the risk of delayed treatment. As a conservative estimate, a treatment delay of 3 months could lead to a >50% relative increase in the number of eyes with vision [≤]6/60 and 25% relative decrease in the number of eyes with driving vision at one year.